Podcars Running At London's Heathrow Airport

Modern Personal Rapid Transit, or PRT or podcars, are finally being put to use in London's Heathrow Airport. I have called it a solution in search of a problem, and here they found it the perfect problem: getting people from one point, a parking lot, to a second point, the airport, on demand. Instead of having buses running all the time, one can call for a car when needed. It uses 50% less energy and is moving 800 people a day. Jim Witkin raves in the New York Times, and Richard Gilbert in the Globe and Mail.

What ULTra PRT thinks it's offering is a solution to the "last-mile problem," a constant headache to urban planners. In many American cities, mass transit does a great job connecting the areas where people work to the areas where people live. With one tiny caveat: it roughly connects those two areas. Maybe the rail will take you 95% of the way--and then leave the last mile or two up to you. And often, people individually choose to solve the problem of that last mile with something much less environmentally friendly--a ride in the car parked at the rail station garage, for instance. Some have proposed things like Zipcars and Segways as solutions to the problem--but others, according to a report in Good two years ago, think that personal rapid transit might be the way to go.

What GOOD actually described as the last-mile problem was this:

It isn't the mere lack of trains and subways that keep people in their cars. It's what urban planners call the first- and last-mile problem. You know it, intuitively. Let's say you'd like to commute on public transit. But if you live in a suburb-and ever since 2000, over half of Americans do-it's unlikely that you live close enough to a station to walk. The same problem arises once you get to your destination: You probably don't work anywhere near the closest bus or train station. So even if public transit is available, commuters often stay in their cars because the alternative-the hassle of driving, then riding, then getting to your final destination-is inconvenient, if not totally impossible. "Denser areas don't have these same problems," says Susan Shaheen, who heads the Innovative Mobility Research group at the University of California, Berkeley. "The problem is really about land use in the United States."

So in London, they have spent over at least £25m (US$ 40,000,000) to build a 2.4 mile long system that connects two buildings. How does the model translate to the last mile problem of low density suburbia? Do you build dedicated guideways (estimated by ULTra to be about US$ 13 million per mile) down every arterial road in the suburbs, and then still have a last half-mile problem?

In much of Europe, they have a much better solution for the last-mile problem, a cheap and effective PRT vehicle- the bicycle.

The PRT supporters are a rowdy bunch, and I have been called an ignoramus blogger and even given an award for my stupidity. Perhaps I am; after four years of writing about these things, I still can't figure them out.